Frank Cowper Sailing Tours

[Georgiegirl]

Dear all,

I have been reading a book by Frank Cowper called sailing tours and I am puzzled any a reference to tides I was wondering if anyone would be able to help explain it. Frank wrote a serious of books about sailing around the UK in the 1830's. They are an good read as he gives a description of the local history for each area and talks about currents that current sailing direction don't seem to cover. But I am stumped by a reference to high tide. I quote : it is high water full and change at 10hours and 30 minutes local or 10 hours 47 mins Greenwich. I understand about the local and Greenwich time reference but 10 hours and 30 mins after what? There is nothing that says to refer to liverpool, Dover or anything like that. Does anyone have any ideas?

The area the book is referring to is Anglesey, north wales.

Comments welcome!

[Trident voyager]

Hi

It may be referring to Dover a lot of charts refer to the local standard port ie Portsmouth but the channel charts don't use Portsmouth but use Dover this is common around the UK to use Dover as the reference port if you like. Haven't got my almanac to hand as I;m at work to check the differences between Dover and the North Wales ports but from memory the difference between Belfast and Dover is 10mins.

Read Frank Cowper's Sailing Tours a few years ago the Scottish books very good especially when sailing the areas today and seeing the changes from the things described in his books.

Regards

John

[Georgiegirl]

Thanks for that idea john, but I came across a reference in another old book. Which refers to high water full and change being at the time the new or full moon passes the meridian of that locality. There is a time lag. It says for example the lag at Plymouth 5 hours 23 mins. And each day high water occurs at Plymouth 5hours and 23 mins after the moon has crossed the meridian of Plymouth. It goes on, but I lost the plot. I think this is the common establishment and it is also referred to as the establishment of the port. Am I any the wiser? That would be a no.

Thank heavens for tide tables.

G

[Georgiegirl]

I think I meant time lag!!!!

Corrected, Pete7

[StuM]

I think GeorgieGirl has the right idea.

Lunitudinal Interval. (my Casio watch uses it to estimate the tide).

Good explanation here:
Lunitidal intervals (Maritime Safety Queensland)

[Trident voyager]

Hi

Yes it makes sense now was probably thinking to modern, But certainly thinking full and change is making sense. The frank Cowper books are a good read though.
J

[Strolls]

Originally Posted by Georgiegirl

I have been reading a book by Frank Cowper called sailing tours and I am puzzled any a reference to tides I was wondering if anyone would be able to help explain it. Frank wrote a serious of books about sailing around the UK in the 1830's. … I quote : it is high water full and change at 10hours and 30 minutes local or 10 hours 47 mins Greenwich. …

The area the book is referring to is Anglesey, north wales.

A necro-bump on this olde thread - I've just come across it because this week I've been working on a wikipedia page for Frank Cowper.

• Anglesea's longitude is 4° 20′ west of Greenwich.
• There are 60 minutes in an hour and 24 hours in a day, so 1440 minutes in a day.
• There are 360º around the equator - divide that by 1440 and we see the sun traverses ¼º of longitude each minute of the day.
• ¼º goes into 4° 20′ about 17⅓ times - i.e. local noon in Anglesea is 17⅓ minutes later than in Greenwich.
• This is the same as the difference between the two times given in Cowper's Tours.

I hope I have expressed myself clearly, and that my maths hasn't betrayed me.

I believe it was around the early 1890's that Cowper circumnavigated Britain, but if it was the 1830's then most places were still using local noon. The railways started using London time in the 1840's, and in 1880 GMT was legislated as the national time.

Supposing that Cowper had a pocket watch on his 1890's voyages, it wouldn't surprise me if he set it by noonsight.

I hope this is helpful.

• Background on the United Kingdom's Time Zone

[Littlechay]

On charts up until quite recently (fifty years back or so) tides were given as HW F&C and indeed there are still modern charts like that; some from Chile for instance.

HW F&C means High Water Full & Change and it refers to the local time of high water at the Full and New Moon. To get the time of the tide for intervening days you add 50 minutes each day.

It is perfectly good for most navigation and once you know the time of HW F&C you can do the sums in your head. No need for tables and such.

Chris
--
http://www.tweedsworld.